The invention relates to an exhaust gas recirculation device for an internal combustion engine in which the exhaust gas recirculation device is connected to an exhaust manifold of an exhaust system of the internal combustion engine to recirculate the exhaust gases to the air intake channels of the internal combustion engine. The exhaust gas recirculation device has a housing containing a valve including a disk-shaped element attached to a rotary drive shaft to control flow of the exhaust gases through openings in a control element to the air intake channels.
An exhaust gas recirculation device is disclosed in DE-A199 41,035 which cooperates directly with the air intake channels of the internal combustion engine. A connection element of an exhaust gas recirculation valve is adjusted by a drive shaft running along the air intake channels. This embodiment takes up a relatively large space and is sensitive to disruptions from external influences.
An object of the invention is to avoid these disadvantages and to provide an exhaust gas recirculation device, which is compact and is insensitive to disruptions from external influences.
This object is achieved according to the invention in that a drive module for a rotary slide valve is provided directly on the housing. In this way, a very compact structural arrangement of the exhaust gas recirculation device is obtained. This compact embodiment also reduces sensitivity to disruptions, since the drive module and the exhaust gas recirculation valve are no longer arranged separately in the engine space. The drive module is connected to a rotatable shaft of the disk-shaped element by means of a coupling constructed as a universal joint. It has been found advantageous if the openings in the control element have a defined geometrical shape, such as, circular, elliptical, polygonal and the like, so that a specific flow characteristic can be defined. Ceramic material has proven advantageous as the material for the control element. The control element is provided with scraping edges, which are in contact with the disk-shaped element in order to keep frictional forces between the disk-shaped element and the control element as small as possible. The disk-shaped element can be circular in cross-section for a four-cylinder internal combustion engine and provided with appropriate passage openings. Alternatively, it can be made cruciform in shape with the openings formed between adjacent legs of the cruciform shape. The disk-shaped element is urged against the control element by a spring, so that the sealing function of the exhaust gas recirculation valve is assured, and it is particularly advantageous for the disk-shaped element to be driven via the universal joint.